1. Field of the Invention
The present invention relates in general to automotive hand tools, and more specifically to an automotive hand tool for draining automobile oil filters prior to removal of the filter from an automobile's engine.
2. Description of the Prior Art
Practically all engines (including those used in automobiles) utilize an oil lubrication system which incorporates an oil filter to filter the oil that is circulated throughout the engine. Typically, the oil filter is removably and sealably fastened to the engine itself, either by being screwed onto a threaded receptacle or by being held by clamps or other fastening means. Once installed, the oil filter functions like a sieve by catching and retaining harmful particulates found in the oil as the oil passes through it, thus removing these particulates from the circulating oil stream. Oil filters are typically constructed such that oil flows from the engine and into the filter through one or more inlet orifices, after which the oil flows into an interior circumferential chamber, then inwardly through a multi-layered paper filtering portion, then into an interior axial chamber, and finally back out of the filter and into the engine. Periodically, old particulate-laden oil filters must be removed and replaced with new oil filters.
There are a number of problems associated with the changing of oil filters. First, oil filters are often located in hard-to-reach areas on an engine, making it difficult to conveniently reach the oil filter by hand or otherwise. As automobile manufacturers increase the number and complexity of systems and components attached to the engine, accessing the oil filter becomes more and more difficult.
Second, changing an oil filter is messy. Whenever an oil filter is removed from an engine, the seal between the filter and the engine is broken and often some of the oil remaining in the filter is spilled onto the engine or other components below as well as on the person removing the filter.
Third, oil spillage is not only messy, but is also environmentally undesirable. Oil spilled during oil filter changes spills not only on the engine and surrounding components but also on the work area beneath, and even onto the roadways as it continues to drip from components onto which it spilled. Cleaning up this spilled oil is difficult and often requires the use of environmentally harsh cleaning compounds.
Prior attempts have been made to address these problems. In order to provide background information so that the present invention may be completely understood and appreciated in its proper context, reference may be made to two prior art patents as follows:
U.S. Pat. No. 5,299,714 discloses a device for draining and removing vehicular oil filters by puncturing the filter with the sharp end of the device; allowing the oil within the filter to drain out through the hollow inner portion of the device; and, once the filter has been drained, using an oil filter wrench in conjunction with another socket wrench to unscrew the filter from the threaded engine receptacle to which it is attached. However, this device has a number of drawbacks. First, the sharp, exposed end of the device is dangerous because it can easily scratch or puncture people or objects with which it comes in contact. Second, the distance between the tip of the puncturing end of the device and the base of the penetrating surface against which the resilient washer is disposed appears to be fixed. This may result in said distance being too short to allow puncture into the innermost chamber of long or large filters, or being too long to allow the outer filter wail to seal against the washer when puncturing small or short filters. The result in the former case is incomplete drainage of oil from the punctured oil filter, while the result in the latter case is a lack of or inadequate seal between the filter and the washer (further resulting in oil dripping uncontrollably from the puncture). Third, in using the device with some filters, it is possible for the device to penetrate the filter too deeply so as to not merely make a puncture in the filter wall, but also to cut out an entire circlet of the wall. This loose circlet has the potential of clogging up or restricting the flow through the device. Fourth, when using the device with its valve closed (so that the interior of the device serves as a reservoir), there is no easy way for the user of the device to determine how full the reservoir is. Fifth, given the wide variety of locations on an engine where the oil filter might be mounted as well as the variety of hoses, wires, and other interfering structures proximate to the engine, it may be difficult to position the non-puncturing end of the device while it is still engaged with the oil filter so as to allow for easy drainage through the device into a separate receptacle.
U.S. Pat. No. 5,390,823 discloses a device similar to the '714 invention mentioned immediately above, with the added feature of having a detachable handle portion, yet without the male oil filter socket wrench component, without the female socket wrench component, and without the resilient washer or any other means to seal the device against the punctured filter wall. The '823 invention also has the same drawbacks as the '714 invention, except that the '823 invention has no resilient washer or other means for sealing the device against the punctured filter, thereby creating even more of a leaking problem for this invention than for the '714 invention.
The present invention overcomes all of the above mentioned problems, while also providing several beneficial features not contemplated by the prior art.